Hall sensors, fluxgate sensors or flipcore sensors are presently used in consumer electronics to detect a direction and/or strength of a magnetic field. The sensor element usually includes a closed or open ferromagnetic core, a field coil with single or multiple windings, and a detection coil with single or multiple windings. A control circuit of this type of sensor element normally generates a periodic signal from a corresponding source. The control circuit is independent of the position of the sensor element. Thus, in such cases the sensor element may be situated on the same semiconductor material or also on one or multiple materials/substrates. The control circuit of the particular sensors is usually limited to a current starting circuit for one sensor element via two terminals. Two additional terminals are used for the detection coil. A single control circuit may be used, for example, in multiplexed form for multiple sensor elements.
A device is described in German Published Patent Appin. No. 10 2008 042 800 for measuring a direction and/or strength of a magnetic field which has a first sensor for detecting a first component of the magnetic field in a first spatial direction and a second sensor for detecting a second component of the magnetic field in a second spatial direction and a third sensor for detecting a third component of the magnetic field in a third spatial direction. The first sensor includes at least one Hall sensor and the second and/or third sensor include(s) at least one fluxgate sensor.
An evaluation circuit for compensating Barkhausen noise during the magnetic field measurement is described in German Patent No. 10 2009 045 237.
When it comes to high activating currents, present-day circuit topologies are pushed to their limits, since they are unable to achieve a sufficient drive capability. The limited drive capability is related to the resistance of the sensor element. The number of coil windings of the field coil determines the magnitude of the generatable/detectable magnetic field; however, though multiple windings of a coil bring an improvement with regard to the detection of higher magnetic fields, they bring major disadvantages for the control circuit due to the increase in the coil resistance.